//  PseudoRandom.java
//
//  Author:
//       Antonio J. Nebro <antonio@lcc.uma.es>
//       Juan J. Durillo <durillo@lcc.uma.es>
//
//  Copyright (c) 2011 Antonio J. Nebro, Juan J. Durillo
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
// 
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.

package etmo.util;

/**
 * Class representing a pseudo-random number generator
 */
public class PseudoRandom {

	/**
	 * generator used to obtain the random values
	 */
	private static IRandomGenerator random_ = null;
	private static RandomGenerator defaultGenerator_ = new RandomGenerator();

	/**
	 * Constructor. Creates a new instance of PseudoRandom.
	 */
	private PseudoRandom() {
		if (random_ == null) {
			// this.random = new java.util.Random((long)seed);
			random_ = new RandomGenerator();
		}
	} // PseudoRandom

	public static void setRandomGenerator(IRandomGenerator generator) {
		random_ = generator;
	}

	/**
	 * Returns a random int value using the Java random generator.
	 * 
	 * @return A random int value.
	 */
	public static int randInt() {
		if (random_ == null) {
			random_ = defaultGenerator_;
		}
		return random_.nextInt(Integer.MAX_VALUE);
	} // randInt

	/**
	 * Returns a random double value using the PseudoRandom generator. Returns A
	 * random double value.
	 */
	public static double randDouble() {
		if (random_ == null) {
			random_ = defaultGenerator_;
		}
		// return random_.rndReal(0.0,1.0);
		return random_.nextDouble();
		// return randomJava.nextDouble();
	} // randDouble

	/**
	 * Returns a random int value between a minimum bound and maximum bound
	 * using the PseudoRandom generator.
	 * 
	 * @param minBound
	 *            The minimum bound.
	 * @param maxBound
	 *            The maximum bound. Return A pseudo random int value between
	 *            minBound and maxBound.
	 */
	public static int randInt(int minBound, int maxBound) {
		if (random_ == null) {
			random_ = defaultGenerator_;
		}
		return minBound + random_.nextInt(maxBound - minBound);
		// return minBound + randomJava.nextInt(maxBound-minBound+1);
	} // randInt

	/**
	 * Returns a random double value between a minimum bound and a maximum bound
	 * using the PseudoRandom generator.
	 * 
	 * @param minBound
	 *            The minimum bound.
	 * @param maxBound
	 *            The maximum bound.
	 * @return A pseudo random double value between minBound and maxBound
	 */
	public static double randDouble(double minBound, double maxBound) {
		if (random_ == null) {
			random_ = defaultGenerator_;
		}
		return minBound + random_.nextDouble() * (maxBound - minBound);
		// return minBound + (maxBound - minBound)*randomJava.nextDouble();
	} // randDouble
} // PseudoRandom
